Contents

Plants come in varieties that are either cultivated or grow wild. Cultivated plants are planted by colonists in a growing zone or a hydroponics basin, mainly for food. Wild plants grow naturally throughout the map. Some wild plants spread themselves via seeds. Animals mostly graze on wild plants but will happily eat cultivated crops as well, including tamed animals. Since Alpha 17, they leave ash on the ground when burnt.

Growth Rate Factors

Fertility

Most plants have a <fertilityFactorGrowthRate>, which is used to determine how "picky" a plant is about how fertile its terrain needs to be. A plant with a <fertilityFactorGrowthRate> of 0 will not care if it is planted on fertile soil or sand; it will grow at the same rate on any terrain tile that will accept its roots. In contrast, a plant with a <fertilityFactorGrowthRate> of 1 will not grow so well if it is planted on anything less fertile than standard soil.

Temperature

For normal growth rate, plants require temperature between 10 °C (50 °F) and 42 °C (107.6 °F). Plant growth rate drops by 10.0% for each degree Celsius below 10 °C (50 °F), and by 6.25% for each degree above 42 °C (107.6 °F). The plant's info window will show 'Out of ideal temperature range (growing at xx% of normal speed)'. Plants will not grow when the temperature falls below 1 °C (33.8 °F) or rises above 57 °C (134.6 °F). The plant's info window will show 'Out of ideal temperature range (not growing)'. If the temperature drops below -10 °C (14 °F), it will either die or lose its leaves, depending on the type of plant. Leafless plants cannot grow, and will take a full day to regrow their leaves after the temperature rises back above -2 °C (28.4 °F).

Light

Plants typically require at least 50% light to grow. This minimum light value can be modified by changing a plant's <growMinGlow> value. When a plant lacks adequate light its info window indicates this with the text 'Needs light level: ##%'. At adequate light levels (50% standard), plant growth rate will start to rise. A plant's growth rate will increase until it reaches its optimal light level (100% standard). A plant's optimal light level can be modified by changing its <growOptimalGlow> value. In areas which lack light, usually indoors with a hydroponics basin, a sun lamp provides 100% light. Plants may even grow at a modest 20% rate when lit by a standard lamp which provides 60% light.

Rest

All plants rest from hour 19 through hour 4. More accurately, plants rest for 45% of the day, leaving 55% of the day for growing.
During the plant resting time period, plants will not grow no matter the light level.
A new constant, Growing Ticks/Day, can be found by multiplying Ticks/Day by 0.55

Growing Ticks/Day = (60,000 Ticks/Day × 0.55) = 33,000 Ticks

Instant Growth

All plants receive an instantaneous growth of 5% when sown/planted.
This is relevant because it means that all plants only need to grow 95% from the moment they are planted to become fully grown (100%).
You'll see this show up in a later equation as a new value: Growth Remaining
You can use this value to help determine how long a plant has left before it is fully grown.

Actual Growth Time

The Growth Time displayed in-game can tend to confuse a player into thinking a plant will be fully grown in X number of days.
Due to the various Growth Rate Factors (Fertility, Temperature, Light) and every plant's need to rest, the growDays or "Growth Time" listed in-game is not an accurate/intuitive representation of how long a plant actually takes to grow.
For example: A Raspberry Bush (3:growDays), on Soil (1:Fert), experiencing optimal temperature and light 100% of the time (1:Temp, 1:Light), will take approximately 5.18 actual in-game days to grow.
It is important to remember this when setting up your growing zones.

Lifespan

The lifespan of a plant is calculated by simply multiplying the plant's growDays by its lifespanFraction.
Most vanilla plants have a default lifespanFraction of 3; Roses being the exception, with a lifespanFraction of 7.
Since plants only grow during certain hours, and growth rate varies greatly under different circumstances, it is possible for a plant to die before it reaches full maturity.